Spin-transfer torque for continuously variable magnetization
Spin-transfer torque for continuously variable magnetization
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DOI：
10.1103/physrevb.73.054428
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发表时间：
2006-01
影响因子：
3.7
通讯作者：
Jiang Xiao;A. Zangwill;M. Stiles
中科院分区：
文献类型：
--
作者：
Jiang Xiao;A. Zangwill;M. Stiles
我们报告的自旋电流和自旋转移力矩的量子和半经典计算的自由电子斯通纳模型的磁化强度在一维连续变化的系统。分析结果得到了一个无限的自旋螺旋和数值结果得到了现实的畴壁轮廓。绝热极限描述了传导电子自旋，其遵循交换场和由壁中的磁化梯度产生的有效的速度依赖场的总和。非绝热效应出现短畴壁，但其幅度呈指数下降的壁宽增加。我们的研究结果怀疑最近提出的非绝热贡献的自旋转移力矩由于自旋翻转散射的存在。
We report quantum and semiclassical calculations of spin current and spin-transfer torque in a free-electron Stoner model for systems where the magnetization varies continuously in one dimension. Analytic results are obtained for an infinite spin spiral and numerical results are obtained for realistic domain wall profiles. The adiabatic limit describes conduction electron spins that follow the sum of the exchange field and an effective, velocity-dependent field produced by the gradient of the magnetization in the wall. Nonadiabatic effects arise for short domain walls but their magnitude decreases exponentially as the wall width increases. Our results cast doubt on the existence of a recently proposed nonadiabatic contribution to the spin-transfer torque due to spin-flip scattering.